diff --git a/Python/thread_pthread.h b/Python/thread_pthread.h
index 995ef51dc52..24f8f4e368b 100644
--- a/Python/thread_pthread.h
+++ b/Python/thread_pthread.h
@@ -120,6 +120,9 @@ typedef struct {
  */
 static void _init_thread _P0()
 {
+#if defined(_AIX) && defined(__GNUC__)
+	pthread_init();
+#endif
 }
 
 /*